Trait-mediated density-dependence and community level eco-evolutionary dynamics

科学家通过观察、实验和数学建模的混合来实现对系统的良好理解。如果生物学家能够建立一个模型，可以用来准确预测野外种群和群落的行为，他们就对这个系统有了很好的理解。不幸的是，对于大多数自由生活的人口和社区来说，构建这样的模型是一个真实的挑战。这有几个原因。首先，收集足够大量的观测数据来建立稳健的参数化模型是耗时且昂贵的。第二，大多数自然系统不容易进行实验操作，而实验操作在获得仅靠观察无法获得的洞察力方面是无价的。第三，当系统受到干扰时，种群和群落的多个方面往往会同时发生变化，包括种群规模的动态、青少年和成年人的平均体型、基因频率和出生时预期寿命等生活史特征。直到最近，生物学家才开始研究如何同时模拟种群、基因和性状的动态。这些模型被称为积分投影模型，虽然积分投影模型为理解自然系统的动力学提供了巨大的潜力，但其发展仍处于起步阶段。特别是对同一物种个体之间竞争的处理是天真的。此外，还有相当多的工作要做，使用这些模型来探索社区内物种相互作用的方式。在本提案中，我们将从已经发表的积分投影模型开始，这些模型包括同一物种个体之间的竞争，并将使用新的方法来分析它们，以全面了解个体之间不同类型的竞争如何同时影响种群规模，体型和生活史的动态。接下来，我们将使用来自特立尼达岛淡水鱼群落的一些非常详细的实验数据来建立物种相互作用的模型。我们将使用这些模型来预测自然河流的动态，其中动态已经观察了多年。因此，拟议的工作非常物有所值，因为我们将使用如此广泛的现有数据。通过对我们的模型进行一系列分析，并可能进行一些额外的实验，我们希望建立能够准确捕捉自然溪流群落动态的模型。在工作结束时，我们希望能够比任何其他正在研究的自由生活社区更好地了解这个系统的动态。

Scientists achieve good understanding about a system through a mixture of observation, experimentation and mathematical modeling. If biologists can build a model that can be used to accurately predict the behavior of populations and communities in the wild, they have a good understanding of the system. Unfortunately constructing such models is a real challenge for most free-living populations and communities. There are several reasons for this. First, it is time consuming and expensive to collect a sufficiently large quantity of observational data to robustly parameterize models. Second, most natural systems do not easily lend themselves to experimental manipulation that are invaluable in gaining insight that cannot be reached from observation alone. Third, multiple aspects of populations and communities often change together when the system is perturbed, including the dynamics of population size, average body size of juveniles and adults, gene frequencies and life history traits like life expectancy at birth. It is only recently that biologists have worked out to simultaneously model the dynamics of populations, genes and traits. These models are called integral projection models.Although integral projection models offer enormous potential for understanding the dynamics of natural systems, their development is still in its infancy. In particular the treatment of competition between individuals of the same species is treated naively. In addition, there is considerable work to be done to use these models to explore the way species within a community interact. In this proposal we will start by taking already published integral projection models that include competition between individuals of the same species and will use novel methods to analyze them to gain general insight into how different types of competition between individuals simultaneously impacts the dynamics of population size, body size and life history. Next, we will use some exceptional detailed experimental data from a freshwater fish community in Trinidad to build models of interacting species. We will use these models to predict the dynamics of natural streams where dynamics have been observed for many years. The proposed work is consequently exceptionally good value for money because we will use such extensive existing data. Through a series of analyses of our models, and potentially some additional experiments, we expect to build models that accurately capture the dynamics of the natural stream community. By the end of the work we expect to have achieved a better understanding of the dynamics of this system than of any other free-living community under study.